Markers used to differentiate carcinoma from mesothelioma showed immunoreactivity in peritoneal mesothelioma: estrogen receptor (2 of 84; 2%), B72.3 (6 of 196; 3%), CK20 (5 of 116; 4%), CD15 (7 of 192; 4%), p63 (3 of 62; 5%), carcinoembryonic antigen (9 of 199; 5%), PAX8 (12 of 191; 6%), progesterone receptor (5 of 71; 7%), Ber-EP4 (17 of 209; 8%), and CD138 (9 of 91; 10%).
To help differentiate PMM from PPSC and RMH, we used immunohistochemistry to examine mesothelial-associated markers (calretinin, AE1/AE3, CK5/6, CAM5.2, D2-40, WT-1, HBME1, thrombomodulin), adenocarcinoma-associated markers (CEA, BerEP4, MOC31, ER (estrogen receptor), PgR, TTF-1, Claudin-4, Pax8), and malignant-related and benign-related markers (epithelial membrane antigen (EMA), desmin, GLUT-1, CD146 and IMP3), and FISH to examine for homozygous deletion of 9p21.